The present invention generally relates to inkjet spacer applicators, especially to circulating spacer applicators.
Recently, inkjet spacer applicators of which inkjet printer is adapted have been used to apply spacers for liquid crystal display.
Reference 111 in FIG. 9(a) represents an example of a spacer applicator having an ink head 121 retained in a holding frame 120 above a platform 105, and a dispersion liquid of which spacers are dispersed is discharged from the ink head 121 while the ink head 121 and substrate 107 for a liquid crystal on the platform 105 are relatively moved along a scanning direction 109, whereby the dispersion liquid lands at a desired position on the surface of the substrate 107 and the spacer is placed there.
FIG. 8 is a block diagram for illustrating a system for supplying the dispersion liquid of the conventional spacer applicator 111.
In this spacer applicator 111, the ink head 121 consists of a plurality of head modules 121a to 121c each connected to a feed tank 136 placed at a lateral position with respect to the platform 105.
A dispersion liquid 138 is stored in the feed tank 136 to the same height as the positions of discharge holes of the head modules 121a to 121c, and when valves between the feed tank 136 and the head modules 121a to 121c are opened to connect the feed tank 136 and the head modules 121a to 121c and gas is supplied into the feed tank 136 by a pressurizer 130, the pressure in the feed tank 136 increases so that the dispersion liquid 138 in the feed tank 136 is supplied to the head modules 121a to 121c. 
The head modules 121a to 121c are connected to a recovery tank 137 so that the dispersion liquid supplied from the feed tank 136 flow through the head modules 121a-121c and then returns to the recovery tank 137.
The recovery tank 137 and the feed tank 136 are connected to each other, whereby the dispersion liquid 139 recovered in the recovery tank 137 can be returned to the feed tank 136. These conventional art are disclosed in, for example, JPA2004-50059, JPA2002-72218 and JPA11-7028.